verhoevenc

One more for good measure. This is the sister set that I pulled out this morning. Black and blue soaks followed by a pull in yellow. This is a much thinner billet so the soaked colors will likely be more drastic inside than the one above.

Chris

So that one I talk about above that I resawed after the initial soaks... to see how far color would penetrate... looks like this. The left side is what the "outside" looks like, the right side is what the inside bookmatched face looks like.

Chris

There's not really much... once they are resawn down thinner. Obviously anything 3/4" thick (where my billets start to get a 1/4" bookmatch in the end) will not want to move. And I'm capable of resawing a curved board all day. So that's not a problem. The real issue comes with putting a warped board in the cactus juice and the vacuum chamber. The more warped the board, the deeper the juice bath must be, and the deeper the tray it sits in. Since the chamber is round... that means the less wide the board can be.

Its all very connected. So I'm still of the opinion that dealing with keeping the billet flat through to the end, as much as possible, is worth it.

Chris

Ugh... I should go replace the missing pics... thanks for the policy change Photobucket!

i wanted to give another update though for now. I believe I've solved the 'large pieces warp in the oven' issue! Had some good luck following these procedures:

1- go from you ambient MC% to ~4% very slowly. For this I'm using a food dehydrator/jerky maker box.

2- still go 24hrs+ in the oven to get to 0% MC

3- ANY TIME YOU PUT ANY TOP IN THE OVEN, weight and sticker it! I've also found that a top/bottom buffer so one side of the wood isn't always facing one heating element or the other. Is good. My sandwich goes: Plywood, stickers, foil (to catch any bleed out only), stickers (covered in foil so they don't stick to the wood), plywood, rocks for weight.

Chris

I'll play. Here's the latest finished project. This is actually the "twin" to my July entry. I say that because minus wood and finish differences, different neck pickup, and added binding... it's essentially the same guitar. They were made in tandem on the CNC with only minor tweaks to the GCode. This one was always the guinea pig for the cuts on the customer's version as these were my first guitars where the majority of routing was done on the CNC.

Neck: 25.5" scale, 1-11/16" nut figured Katalox board on an African Mahogany bolt-on neck.

Body: Thinline swamp ash with a holly burl (locally harvested) top with black pearloid binding.

Electronics: Tele style 4-way (series/parallel) with a McNelly A2 Signature bridge and Benson JM style neck.

Let's start with a video of someone playing her at a recent event:

Best,

Chris

What are the best woods to practice on? Anything... the darker they are the more they'll hide mistakes though. But for practice... who cares... seeing your mistakes loud and clear may be a good thing.

What is a good/cheap inlay material to practice with? Again, anything you can cut with a saw. Plastics from around the house. Shell "seconds" can be had pretty cheap and will obviously be more realistic for your ultimate goals.

What are the minimum tools I need? Rotary tool (like a dremel) with a nice router base. Router bits (I'd suggest 1/32", 1/16" and 1/8"). Jeweler's saw. Mini file set (Home Depot's are fine).

Is a router/dremel essential or can you do inlay with just chisels? I wouldn't suggest it... it's possible but I'm betting it'll turn you off it.

If you can use just chisels how do you get the bottom flat? Good luck lol

What are the best ways to get the inlay material flush with the surface of the wood? Sand it once you've inlaid it... 

Is there a resource that can tell me what woods are toxic and should only be worked on with a breathing mask and ventilation? To my knowledge there are no "toxic" woods... at least that luthiers commonly work. There are woods that are known allergens for the general population (like cocobolo). It's always a good idea to wear a mask, period. Wood dust in general isn't great for your lungs, especially if you plan on doing this for a long time.

Best,

Chris

My rule of thumb? Make the joint super tight when dry and right off the router. Sanding will then take away the material needed to allow for glue, fiber swell, etc.

Chris

Note: This is for set neck joints. For bolt ons I (now that I have a CNC) tell the CNC to give me a .010" offset for a total difference of .020" in width right off the table.

Ok, last post on boring tests and numbers for the day; promise.

These are the sizes of the chips being produced by the .002 chipload. They eyeball at around .002" thick so that seems logical.

This is the shape I did. Grain runs left to right.

End grain side 1 is incredibly smooth.

End grain size two has some very minor fuzziness... but still nothing compared to what I've been dealing with before (was previously running this bit at 1.33IPS @ 12k... so a chipload of .00665).

Here's the side grain. Again nice.

Other problem I still seem to have is chunks of wood being lost in sections of extremely short grain (think the corners of headstocks...). This I'll still have to run tests to alleviate.

All in all I think I have found my desired chipload for this one bit (hahahaha). I'm also fairly confident that if I were to run these cuts with a .015" offset and then come back and do a full-depth onion-skin pass to remove that last bit that I would be left with stellar results. I wish I'd have thought to test that while everything was still on the table...

Chris

No kidding a starting point! OK, so I ran some tests... and by that I mean a lot of tests. Basically draw a ton of lines and cut them at every possible feed/speed combo that I could (within reason for jumps in IPS and RPM). All of this was done with an Onsrud 65-000 (single flute upcut O-flute) endmill. According to Onsrud's chipload chart (https://www.onsrud.com/files/pdf/2012 LMT Onsrud Production Cutting Tools Hard Wood.pdf) this bit has a recommended chipload in hardwood of .004-.006

With this in mind I set up the following 3" lines, .2" deep, single pass:

• 9000RPM
  • 1IPS= .0067 <- best of the 9000RPM tests
  • 2IPS= .013
  • 3IPS= .02
  • 4IPS (my machine's max cut speed)= .026
• 12000RPM
  • 1IPS= .005 <- best of the 12000RPM tests
  • 2IPS= .01
  • 3IPS= .015
  • 4IPS= .02
• 15000RPM
  • 1IPS= .004 <- best of the 15000RPM test
  • 2IPS= .008
  • 3IPS= .012
  • 4IPS-.016
• 18000RPM
  • 1IPS= .003 <- best of all the tests so far
  • 2IPS= .006
  • 3IPS= .01
  • 4IPS= .013

Looking at the channels and judging them for cleanliness I found that .003 chipload in the 18000RPM bracket was the cleanest. My definition of "clean" wasn't just cut marks being left by the bit, but more importantly a lack of tearout as all the tests purposefully cut across end grain, which is the only real place I'm having cleanliness issues when cutting out guitars.

It was surprising to see that the lowest value was the winner; especially since it was out of Onsrud's recommended range. Note, only two other values were within their range though; .004 and .005

With this new knowledge I went back and calculated chiploads of .001-.004 in .001 increments, all at 12000RPM (as this is what I've been told is ideal for wood). The results of these tests are:

• .001 as .2IPS
• .002 as .4IPS <- winner
• .003 as .6IPS
• .004 as .8IPS

Although .001 was very nice and clean, I could see that the "chips" coming off this cut were very small. Seeing as .002 was just as clean, had nicer chips, and is twice as fast, this was the winner. .003 and .004 both started to show signs of tearout of the end grain.

In conclusion the winning chipload for this bit is not only outside of the manufacturer's recommended range, but also a mere 50% of the recommended range's lower bound?! Can this be right? I'm going to do some more extensive tests with this chipload value... but I find it hard to believe that the manufacturer recommendations are so off?

Chris
PS: The wood used was quartersawn sapele scraps.

@Prostheta that video's from long enough ago I forget exactly what all it says (without watching it again of course) but I do do what you're talking about. I've made neck joints that were so tight that when I added glue the neck wouldn't go in! This is not fun because you work your quickest to pull the neck out (it goes in a bit before it binds up) and clean all the glue off all the surfaces.

Unless I'm not putting a neck pickup I much prefer to make my pocket too long so that I can set the neck "loose" and pull it forward to lock in that sideway pressure.

Chris

My main complaint is that the string sits to far off-center on each barrel. Even if you don't use the rear anchors, and instead do a string-through-body mount, there's still not adequet down-pressure on the saddles to make the height-adjustment screws seat well. Basically, the low down pressure issue, mixed with the off-center nature of the barrels, means without endless re-tweaking and perfecting chances are a string or two will sit on either only one height-screw, or there won't be enough pressure to keep one height screw from being lose. This all means buzzing. Granted, I could find my ideal setup and then throw some locktite on the set screws. Total legit, others have done it (especially on jazzmasters and mustangs for similar reasons). But for a for-sale guitar I didn't feel that was the best decision for buzz-avoidance. A new bridge was.

Chris

Your's!

Chris

I have a 6-barrel style (http://www.wdmusic.com/tele_bridge_vintage_6_saddle_chrome.html) tele bridge that I hate! Luckily it has the same hole pattern as my favorite bridge, the Gotoh Modern, and I have switched it out. I repeat, I hated this 6-barrel bridge.

However, obviously someone likes them because they make them and sell them. With that in mind, if you want it, it's your's. All you have to do is send me the USPS/UPS/FedEx label (aka: you cover shipping cost) to stick to the package and I'll ship it out.

It is the chrome one. It's been installed on an instrument and then removed, but not "used." The only real blemish is where the height adjustment screws nicked up the chrome a bit as the saddles were moved to adjust for intonation.

Chris

@MiKro are those numbers correct...?! A 4-flute bit for wood? At an effective chipload of .00145 (tiny!). This seems to go against most things I thought I'd learned about chipload.

Agree might be 'tramming.'

@curtisa I'm sure that's likely help as if you switch direction it leaves the tesrout on the other side. So yes it could be strategically avoided. But what a PITA. I don't see anyone else having to do that so there must be an easier way?

Chris

Spindle is 1HP and the standard Shopbot Desktop offering in the spindle space. Bits aren't coated. Onsrud carbide stuff, this one in particular is the 63-727. Believe the collet is an ER20...?

Chris

So although I feel I'm getting a pretty good handle on the CNC stuff lately there is one thing that continues to remain elusive to me: really clean body route edge.

First I'll describe what I'm doing. Then what I've seen others doing and what I believe are the other options.

Ok. So I started off using a 2-flute spiral upcut (for chip clearance) and that seemed to work ok. However in order to get the chipload where it needed to be I was running my machine at a faster feed rate than I wanted to; 3IPS at 12,000RPM. My machine's max cut is 4IPS and after I had it lose some steps going at 3IPS I was told on a Shopbot forum not to push that boundary. Plus, it wasn't the cleanest cut so I was happy to try other stuff. I went out and got a spiral O-flute single-flute 1/4" bit instead. The flute decrease and chipload recommendation brought my suggested feed down to 1.33IPS which I felt better about. This made for greatly improved chip clearance (bigger flute and slower speed in guessing) and I saw none of the lost steps issues I saw before. Whether that's due to speed or improved chip clearance I do not know.

However, my surface quality didn't appear to go up much. I even went about doing my initial channel .015" offset and then coming back in and 'onion skinning' conventional cut that last little bit. Alas, still some bad spots as you can see in the pic below of a student body that used exactly that method.

The body was flipped half way through and you can see that the bit left rough patches in the same section, as per rotation vs grain direction, on both sides.

Heres what I think is happening. A 1/4" bit isn't THE most rigid thing in the world. When you tell it to go into a 1/4" hole, clear chips while it's at it, and cut cleanly, it's telling me that that's too much to ask. I'm guessing there's too much binding going on, or friction, or heat, or something in that small channel. The .015" onion skin pass was then not thick enough to remove all the chatter?

What I've seen others do, or what my head thinks might be an improvement:

1- do the pass where the bit is the same diameter as the whole channel a full 1/16" offset out. Come back and take off the last 1/16" in a second round. This gives the bit breathing room and also allows you to vacuum out all the chips from round 1 to help clear the channel between paths.

2- Leave indexing pins at a couple locations so you can re-locate the body later. Then mill an 1/8" deep body outline into the blank. Pull it off the CNC and bandsaw it really close the that line. Re-attach to the CNC and route the outline full depth. This would mean you're edge routing, not even routing a channel.

3- move to a 1/2" bit that's more rigid. I don't particularly want to do this as this then requires my blanks to be larger to continue to accommodate the placement of my indexing pins. Seems like wood waste. Also, I've never used a 1/2" bit on my Shopbot Desktop despite it coming with a 1/2" collet. Not sure about the machine's performance with one ATM.

It could also be that I'm doing something else wrong... happy for insight that saves me experimentation time.

Chris

Re-coup your costs? If you're building on his behalf... wouldn't HE be the one in need of re-coup?

Chris

Correct. Sorry, I just used a JM pickup as an example, not as some archetype for this problem.

I get that a strat doesn't get much besides foil tape. Which is essentially the same things as the shielding paint. However, on a strat you can tape the cavities and pickguard and call it a day, cause when assembled, all of the foil pieces touch each other and create your full cage with path to ground. On a guitar without a pickguard you have one shielded cavity (pickup cavity) and another, totally disconnected, cavity that's shielded for the controls. Control one is easily connected to ground... however, the pickup cavity one is not. It's only path to ground is through a tiny holes where the pickup wire goes. Without somehow connecting the shielding paint of the pickup cavity to that of the control cavity, I might as well not have even painted the pickup cavity. Hence: running paint through that little hole too.

Note: another acceptable answer (which I've tried and liked less) would be to run a ground wire between these cavities and solder/screw-attach it to the shielding of your various cavities.

Chris

Given my post's battle cry I think we all know who I voted for haha. That finish is just too cool and original not to vote for.

@Prostheta I'll admit my action shots have been much diminished lately. Most of them go to my company Instagram account as it's easier, faster, and serves a business purpose. But I agree I should get back more to my roots of teaching and sharing. PM me and let's discuss setting something up or other ideas? While you're at it can we up my message storage ?

Chris

I do use shielded wire, but that would assume the wire touches the pickup cavity wall before going to the control cavity. OR that the pickup in question has a shielded back (like the metal humbucker base). But let's say I have a jazzmaster pickup (even with a shielded cable)... it has no sheilded backing and therefore relies on the cavity's shielding. That shielding needs to be connected to ground too.

Chris

I was waiting on pipe cleaners to paint the cable channels I drilled between cavities. Once that's done and all the risk of more spots has abated I'll give the buff a try. I seem to remember a hand buff not being enough in the past, but maybe a true BUFFING compound dab will do more than the polishing compound I tried?

Chris

Has anyone ever gotten some shielding paint on their nitro finish and not noticed until later when it was too dry to just wipe off? Even if you flake it off (comes off easily) the splash/drop will still leave a little shiny, silvery dot where it was.

Anyone know how deep these go into the finish? Suggested removal techniques? It'd be great not to have to sand/buff and risk going through any finish.

Chris

Yeah... doesn't look like they have much in the bass pre-amp arena.

Chris

THAt so far has been my experience. No response to inquiries. I'll peek at DiMarzio's bass pre-amp offering.

Thanks,

Chris